Control means for an indicator



April 9, 1957 R. B. BLAND CONTROL MEANS FOR AN INDICATOR 5 Sheets-Sheet1 Original Filed Sept. 4, 1951 mmvrox Pia/M4405. 5444/0 HTTOR/YEYS April9, 1957 R. B. BLAND vCONTROL MEANS FOR AN INDICATOR 5 SheetsSheet 2Original Filed Sept. 4, 1951 INVENTOR. Riv/N810 a BL/I/YD rraeA/a sApril 9, 1957 R. B. BLAND CONTROU MEANS FOR AN INDICATOR Original FiledSep t. 4, 1951 5 Sheet s-Sheet s IN VEN TOR. PEG/NHZD 5 5L fl/VD pfraeuas April 9, 1957 R. B. BLAND CONTROL MEANS FOR AN INDICATOR 5Sheets-Sheet 4 Original Filgd Sept. 4, 1951 i-a-c-a-iwr AWTOQA/EVS April9, 1957 R. B. BLAND 2,788,399

CONTROL MEANS FOR AN INDICATOR Original File d Sept. 4. 1951 5Sheets-Sheet 5 nrmeuew 2,788,399 CONTROL MEANES FGR AN INDICATORReginald B fiiand, Los Angeles, Calif.

()riginai application September 4, 1952, No. 244,875, now Patent No.2,719,290, dated September 27, 1955. Divided and this application March1, 1954, Serial No. 413,061

7 Claims. (Cl. 200* 6) The present invention relates to improved controlmeans useful in various systems wherein it is desired to represent,either locally or remotely, the position or an element which is movedeither manually or automatically, and constitutes a division of mycopending application Serial No. 244,875, filed September 4, 1951, forRemote indicating and Control Devices.

As will be gleaned from the following description, the present inventionhas universal applicability in systems wherein it is desired to transferindications to a remote location.

The present invention contemplates the provision of improved meanswhereby, for example, the angular position of a shaft may be indicatedeither locally or remotely in terms of numbers in a digital system, thenumbers being used either for indication purposes or for printing, asdesired.

It is therefore an object of the present invention to provide improvedmeans and techniques whereby the above indicated results are obtained.

A specific object of the present invention is to provide an improvedcontroller in a follow-up system in which the controller is associatedwith a remotely controlled element, the position of such remotelycontrolled element being truly representative of the position of themanually actuated controller without the possibility of loss ofsynchronism between such element and controller as is possible insystems incorporating Selsyn drives.

Another specific object of the present invention is to provide animproved controller in a follow-up system of this character in which theposition of a controlled element always bears a predeterminedrelationship with respect to a manually operable control member, eventhough there may be a failure in the power supply in the system.

Another specific object of the present invention is to provide animproved controller in apparatus of this character in which a record ofindicator readings is obtained in the form of printed numerals, eitherlocally or remotely.

Another specific object or" the present invention is to provide animproved controller in a system of this character, as described in thenext preceding paragraph in which an operator may obtain a printedrecord of indications.

A further specific object of the present invention is to provide animproved controller in a system of this character, mentioned above,characterized by the simplicity and inexpensiveness of the controller.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. This inventionitself, both as to its organization and manner of operation, togetherwith further objects and advantages thereof, may be best understood byreference to the following description taken in connection with theaccompanying drawings in which:

Figure 1 is a schematic representation of apparatus embodying featuresof the present invention;

Figure 2 is a view in side elevation of solenoid actuated mechanismsillustrated as solenoid coils in Figure 1;

hired States Patent 2,788,399 Patented Apr. 9, 1957 Figures 3 and 4 areviews taken, respectively, on corresponding lines 3- 3 and 4-4 in Figure2;

Figure 5 is a view showing in enlarged form a portion of the apparatusillustrated in Figure 2 with certain parts sectioned for purposes ofillustrating internal structure;

Figures 6 and 7 show parts of the structure illustrated. in Figure 2 andserve to indicate the manner in which certain adjacent solenoid actuatedmechanisms are interlocked;

Figure 8 illustrates a modified solenoid actuated mechanism for use inthe system illustrated generally in Figure 1;

Figure 9 is a perspective view showing a control illustrated inschematic form in Figure 1;

Figure 10 is a longitudinal sectional view through the control shown inFigure 9;

Figure 11 is a sectional view taken substantially on the line 1111 ofFigure 10;

Figure 12 serves to illustrate the contact arrangement on the innerrotatable rotor of the control shown in Figure 9;

Figure 13 is a perspective view showing the character of the brushesmounted in the stator of the control for cooperation with the contactsin the rotor illustrated in Figure 12;

Figure 14 illustrates the manner in which the solenoid actuatedmechanism of the character shown in Figure 2 may be connected forpurposes of transmitting information of the character transmitted bypresent-day teletype systems; and

Figures 15 and 16 relate to a modified structure for producingindications on a dial instead of two counter wheels as illustrated inFigure 2.

The apparatus described herein functions to produce a visible indicationby means of the cooperating ten and units wheels 10, 11 in Figure 2,such wheels 10, 11 being moved to different positions in accordance withthe adjusted position of the manually operated shaft 12 in Figure 11.These counter wheels 10, 11 indicate numbers from O to 99 continuously,when and as the shaft 12 is rotated through an angular distance somewhatless than 360. The rotor shaft '12 mounts the rotor unit 13, illustratedin Figure '12, and which carries the insulated contacts a, b, c, d, e,and f, as well as an insulated so-called x contact. These contacts a, b,c, d, e, f, and x are interconnected, as illustrated in Figure 1, withother apparatus and cooperate with relatively stationary contacts on thestator 14, such stationary contacts comprising a series of contactsdesignated as A, B, C, D, E, F and X. The contacts on the rotor 13 aretermed herein as the unit contacts while the contacts on the stator 14are referred to herein as thetens contacts.

As is evident from the following description, the rotor contact arepresents the numeral 0; the contacts a, I) considered jointly,represent the numeral 1; the rotor contact b represents the numeral 2;the rotor contacts I), 0, considered jointly, represent the numeral 3;the contact 0 represents the numeral 4; the contacts c, a, consideredjointly, represent the numeral 5; the contact 0! represents the numeral6; the contacts (1, 2, considered jointly, represent the numeral 7; thecontact 0 represents the numeral 8; and the contacts e, 1, consideredjcin.. represent the numeral 9. On the other hand, the stator contact Arepresents the numeral 00; the stator contacts A, B, considered jointly,represent the numeral 10; the stator contact B represents the numeral20; the stator contacts B, C, considered jointly, represent the nor 1the stator contact C represents the numeral the stator contacts C, D,considered jointly, represent the numeral the stator contact Drepresents the numeral the stator contacts D, E, considered jointly,represent the numeral the stator contact E represents the a s numeral80; and the stator contacts E, F, considered jointly, represent thenumeral 90.

In Figures 1 and the various stator contacts are spaced transversely onthe stator with the various rotor contacts subtending an angulardistance somewhat less than the angular spacing of the stator contacts.Thus, for example, all of the rotor contacts a, b, c, d, e, and fcooperate first with the stationary stator contact A before any one ofsuch rotor contacts engages the adiacently disposed group of statorcontacts A, B. it is noted in Figure 10 that the group of rotor contactsare disposed between the stator contacts C on the one hand and C, D onthe other hand, so that the mechanism in that position is effective totransmit the number 49, is being observed that the stator contacts C, Drepresent the number 50 and the stator contact C represents the number40 and that the rotor contacts are in the position in Figure 10 wherethey are just about to leave the C contact upon rotation of the rotor inthe direction indicated by the arrow 17 in Figure 10. Figure 1represents the the condition wherein the rotor moves an incrementaldistance from the position represented in Figure 10 and in such case therotor contacts e and f are no longer engaged by the stator contact C andthe rotor contact a contacts the stator contacts C and D produce thenext highest reading, namely 50, in the manner described hereinafter.

Various means may be used for mounting the different rotor and statorcontacts in their relative positions, as shown, and for extending leadstherefrom. The various rotor contacts a, b, c, d, e, f, and x arerecessed in the block of insulating material 20 formed as a continuationof the annular metal flange 21 (Figures 10, ll) to which the block 20 isfastened by means of screws 22 and straps 23. The annular flange 21comprises essentially the rim of a wheel having integrally formed hub 24which, as shown in Figure 11, is fastened by means of set screw 25 tothe shaft 12. Also recessed in the block of insulating material 20,which is in the form of a sector, are seven separately insulated wirebrushes 26. These wire brushes 26 are supported as cantilevers as shownin Figure 10 and are resilient so that they are pressed into engagementwith corresponding metal slip rings 27 (Figure 11), such slip rings 27being insulated from one another for being connected to different leads28 which extend outwardly of the control unit for connection to theexternal circuitry illustrated in Figure 1. These insulated slip rings27 are stationarily mounted on the annular insulated bushing 29, whichis keyed'by means of key 30 to the stationary casing or stator 14. Thestator 14 comprises a pair of circular end plates 14a, 14b spaced by theannular dished ring 14c. These three elements, i. e., 14a, 14b, and Me,are secured as a unit by means of bolts 14:: and are provided with thealigned bushings 24 and 33 for rotatahly supporting the rotatable shaft12. The various stator contacts A, B, C, D, E, F, and X are of thegeneral form indicated in Figure 13 and are supported on a block ofinsulating material 34 (Figure 13) which, in turn, may be cemented tothe annular ring 140, with the ends of the spring wire contacts 35projecting through the ring 1 3C for resilient engagement with the rotorcontacts a, b, c, d, e, f, and x, as the case may be. These springcontacts 35 are interconnected in the manner illustrated in Figure 1. Asa matter of fact, in the practical embodiment of the arrangement herein,as illustrated in Figure 11, four of such wire contacts 35 comprise oneof the A, B, C, D, E, F contacts, as the case may be, whereas the Xcontact'comprises only two of such spring wires 35, as indicated inFigure 11.

Now that the physical arrangement of rotor and stator contacts and theirrelationship have been described, a detailed description of the solenoidactuated mechanisms to which such contacts are connected is now given.

There are provided two groups of solenoid actuated mechanisms, one groupcorresponding to tens solenoids and having the reference numerals A, B,C, D, E, F while the other group is termed herein as units solenoids andhave the reference numerals a, b, c, d, e, and 1. Both groups, i. e.,the tens and units groups, are of iden tical construction and for thatreason a detailed description of the tens solenoids A, B, C, D, E, F,sutiices as a description of the units group. Referring to Figures 2, 3,4, 5, 6 and 7, the solenoid actuated mechanisms A, B, C, D, E. F, servegenerally to rotate the counter wheel it a predetermined angulardistance depending upon the particular mechanism or group of mechanismsenergized. The counter or printing wheel it) is mounted on the shaft 4%which is rotatably supported in the spaced bearings $2 on the stationaryframe 43. The shaft 4d carries tion gear 44 which is in constant meshwith the vertically movable rack 45. The rack 45 is mounted on the upperend of a rod 46 to which is keyed the circular plate 47. The rod 46 isslidably mounted in the guide sleeve 48 which in turn is afiixed to thehorizontal stationary frame member 49. In order to assure constantengagement between the pinion gear and the rack 45 so as to avoidbacklash, a torque spring 50 (Figure 3) is provided. This torque spring5% has its lower end attached to the stationary frame 43 and the otherone of its ends attached to the rotatably supported shaft 53., whichcarries the gear 53, such gear 53 oeing in constant mesh with the largergear 54 mounted on shaft as.

The actuating plate 47 and hence the rack 45' are normally urgeddownwardly by the tension spring 55 (Figure 2) which has one of its endsaffixed to the lower stationary frame member 49 and the other one of itsends affixed to the hub on the actuating plate 47. This circularactuating plate 47 may be moved upwardly different vertical distancesdepending upon which one of the solenoids A, B, C, D, E, F or group ofthe same is energized. For this purpose, the limitations of travel ofthe armatures of these solenoid actuated mechanisms are established sothat the counter or printing wheel 19 reads 0 when the mechanism a isenergized, the wheel it} reads numeral 1 when the mechanisms a, b areboth energized; the wheel 16 reads the numeral 2 when the mechanism bonly is energized, etc. For this purpose, the armatures of themechanisms b, c, d, e and are mechanically interlocked in a mannerdescribed in detail later.

Each of the solenoids of the solenoid actuated mechanisms is constructedas shown in section in Figure 5 wherein the solenoid winding on isstationarily mounted on the frame member 49 and has a cooperatingarmature 62 to which is attached the plunger 63, such plunger beingslidably mounted in the bushing 64. The upper end of the plunger 63 isrecessed within the vertically movable sleeve 66. Such sleeve isslidably mounted within the cylinder 65. The cylinder 65 is adjustablysecured by means of set screw 67 to the rod 69, which passes throughaligned apertured portions in the actuating plate 47 and frame member70. The rod 69 has a recessed portion 7i through which a motion limitingpin 72 passes, such pin 72 being affixed to the sleeve 66. The upper endof the rod 69 is engaged by the lower end of the coil compression spring75 which has its upper end recessed in the frame member 43. The rod 69also has adjustably mounted thereon the collar 7 6 maintained inposition by set screw 77. Upon energization of the winding 6%, the plate67 is thus raised an amount which is permitted by means described indetail later. Such motion limiting means in general comprises pivotedlevers 63 (Figures 5, 6 and 7) which serve to interlock adjacentsolenoid actuated mechanisms. It is observed that the solenoid actuatedmechanism A is not thus limited since it is not mechanicallyinterlocked, but in such case the upward movement'of the rod. 69 for themechanism A is limited by engagement of the armature 62 with the lowerend of the bushing 6 (Figure 5). The interlocking plate 68 isint'erlocked on upstanding standards fixed at their lower ends to theframe member 49. This plate 68 is pivoted at a point intermediate itsends and has oppositely extending portions which partially encircle onthe one hand the tubular sleeve 66 and on the other hand the cylinder 65of the adjacent mechanism. Thus, one end of the pivoted plate 68 isadapted to be engaged by the lower flange 66a on sleeve 66 while theother end of the plate 63 is adapted to be engaged by the flange 65a onthe cylinder as. When, as shown in Figure 6, the mechanism B isenergized, the actuating plate 47 is moved upwardly a distance limitedby the lefthand end of lever 68. Thereafter, when the mechanism C isenergized, the plate 47 is raised an additional amount determined by theposition which the lever 68 assumes at that time, it being noted that,since both mechanisms B and C are energized (Figure 7) the plate 47,while moved up an additional distance, may be moved still further uponsubsequent deenergization of the mechanism B. Such step by step upwardmovement of the plate 47 results in rotation of the counter wheel 10(Figure 2).

Similarly, provisions are made for energizing the mechanisms D, E, and Feither singly or jointly with the mechanism having the next succeedingletter so as to rotate the counter wheel 10 to a correspondinglydesignated position. The same is true in the units mechanism whichincludes the mechanisms a, b, c, d, e and f.

The solenoid coils for mechanisms A, B, C, D, E, and F and a, b, c, a,e, and f are connected to the aforementioned contacts in the mannerillustrated in Figure 1.

In Figure 1, one terminal of coils A, B, C, D, E, and F is connected tothe positive terminal of voltage source 1%. Similarly, one terminal ofeach of the coils a, b, c, d, e, and f is connected to the negativeterminal of source 109. The other terminal of coils A, B, C, D, E, and Fis connected, respectively, to the A, B, C, D, E, and F contacts.Likewise, the other terminals of coils a, b, c, d, e, and f areconnected to contacts a, b, c, a, e, and f. in order to assure correctoperation, the X and x contacts are provided. The X contacts areconnected through the winding of relay 101 to the positive terminal ofsource 1011. The x contact is connected to the negative terminal ofsource 100. The winding of relay 102 is connected between the negativetrminal of source 160 and the a terminal. The normally closed switch101A of relay 101 has its fixed contact connected to the normally opencontacts 104, 105 of relay 162. The movable contact of switch 161A isconnected to the negative terminal of source 100 through resistance 106.The movable switch elements 107, 108 serve normally to interconnect oneterminal of coils f and e to corresponding contacts f and e. In otherWords, these connections are made to coils e and f only when relay 102is deenergized, i. e., so long as the winding a is deenergized. Uponenergization of relay 102, the current which would otherwise flowthrough windings e and f flows through the compensating resistance 106,provided, of course, that the relay 101 remains deenergized. The windingof relay 101 has one of its terminals connected to the positive terminalof source 100 and the other one of its terminals connected to the Xcontacts so that relay 101 is energized whenever the rotor at contactengages any one of the X contacts. in this respect, it is observed alsothat the x contact leads the a contact so that relay 101 becomesenergized prior to energization of winding a for purposes describedpresently.

Once the apparatus is indexed, i. e., the wheels 1t). 11 assume astationary position which is representative of the angular position ofthe rotor shaft 12, a record may be made of the indication thus providedby the wheels 19, 11 by closing the switch 110 in Figure 1. In suchcase, the solenoid 111 is energized to produce movement of the printingroll 112 into engagement with the raised numerals on the wheels 10, 11(Figure 2) for purposes of recording same. It is noted that the switch110 and solenoid 111 source 190.

Referring to Figure 1, the rotor contact a is in engagement with thestator contacts C and D to indicate, by the simultaneous energization ofthe coils D and C, the numeral 50. it is observed at this time that thewinding or coil a is also energized; and also the relay winding 102 isenergized to operate the associated relay switches 107 and 108 tothereby assure disabling of circuitry used in energizing, under certainconditions, the solenoids e and 7. This expedient assures the absence ofa false reading of 59- under conditions when, either due to me chanicalmisalignment or wear or other causes, there may possibly be thesituation wherein there is simultaneous engagement, on the one handbetween the rotor contact a with the stator contacts C and D, and on theother hand between rotor contacts e and f with stator contact C. Underthis particular situation, the switching resulting from rotor contacts eand 1 being in engagement with the stator contact C does not cause theenergization of the coils e and (indicating the digit 9) because ofactuation of the relay switches 107 and 108 disabling the circuitryextending to the solenoids or coils e and f.

The likelihood of false readings is likewise prevented due to the use ofthe rotor x contact and cooperating X stator contact at the time or"transition from 19 to 20, from 39 to 40, from 59 to 60, from 79 to 80and from 99 to O0, namely at the time of transition from engagement ofthe rotor with a double stator contact to engagement of such rotor witha single stator contact. Thus, assuming the rotor is in engagement withthe pair of stator contacts C and D and moves in the direction of thesingle D stator contact, then, to prevent false readings occasionedotherwise due to lack of mechanical alignment, wear and other similarreasons, the rotor contact, which leads the rotor a contact, engages thestator X contact immediately before the rotor a contact engages thestator contact D. In this exact position, the relay winding 101 isenergized to thereby open relay switch 101A. Immediately thereafter,when the rotor 11 contact engages the single D stator contact, the unitscoil or solenoid a is energized to indicate the digit 0; and relay 102is operated to disable the circuit extending to the units coils e and fto thereby prevent a false reading of 9 in the event that the e and frotor contacts, due to misalignment or other causes, is still inengagement with the pair of stator contacts C and D when the rotor acontact is in engagement with the single stator contact D. Further,since the rotor x contact is in engagement with the stator X contact,the C solenoid is prevented from being energized since in such case therelay switch 101A is open. Thus, at the time the a rotor contact engagesthe single D contact, a reading of 60 is assured, i. e., only the coil Dand the coil a are energized.

Figures 15 and 16 serve to show means whereby indications otherwiseproduced using two wheels 10, 11 in Figure 2 may be displaced by a pairof rotating pointers 115, 116 which rotate about the same axis forcooperation with indicia on the dial face 117. For this pulpose, thepointer is mounted on the inner shaft 121) which extends through thesleeve 121 and which mounts the gear 122. The gear 122 is in mesh withdriving gear 123. The gear 123 is mounted on the same rotatable shaft asthe gear 124 which cooperates with a vertically movable rack bar 125,such rack bar 125 being attached to the actuating plate 37 in Figure 2.Thus, the pointer 115' indicates the tens while the pointer 116 iscoupled in similar manner to indicate the units. The pointer 111 ismounted on the rotatable sleeve 121, such sleeve 121 carrying the gearwhich is in mesh with the large gear 126. The gear 126 is mounted on acommon shaft 127 with the gear 128. The gear 128 is are seriallyconnected with the voltage for engagement with the rack 129 which isatfixed to they actuating plate 47 of the units mechanism.

In the modified arrangement shown in Figure 14, the

various characters on the keyboard of a conventional typewriter areassociated with normally open switches, and such. switches may beconsidered to have the corresponding-1y designated reference characters,i. e., 1, 2, 3, 5, 6, 7, 8, 9, ti, Q, W, E, R, etc., asshown in Figure14. These switches may be considered as being divided into four layersor series. The first layer of switches, i. e., 1, 2, 3, 4, 5, 6, 7, S,9, ti, each have each one of their terminals connected to the positiveterminals of voltage source 39%. The other terminals of such switchesare connected respectively to one t rminai of solenoid coils 301, 302,363, 304, 395, 3%, 367, 308, 309 and 319, with the common lead of eachof such coils being returned to the negative terminal of voltage source3th). These coils 391-319, both inclusive, may be considered to be anassembly of coils as represented by the coils A, B, C, D, E, and F inFigure 4 with, of course;

mechanical interlocking between the actuating mechanisms as described.The second layer or deck of switches Q, W, E, R, T, 1, U, i, O and Ieach have one of their terminals connected through the soienoid coil 315to the positive terminal of source 3%, the other terminal of switch Qbeing returned to the negative terminal of source 3%, whereas the otherterminals of switches W, E, R, T, Y, U, I, O, and P are connected toterminals of coils see, 3%, sea, 3%, 3th), 397, 3%, 3%, 3%,respectively. in similar manner, the third layer or deck of switches A,S, D, F, G, H, P, K, L, have one of their terminals connected throughsolenoid coil 33rd to the positive terminal of source 36%, the othererminal of switch A being connected to the negative terminal of source3%, whereas the other terminals of switches S, D, F, G, H, J, K, L, andare connected respectively to one terminal of coils v3M, 3&3, 394, 365,3%, 397, 3&3, 3%, 310; similarly, the fourth layer or deck of switcheseach has one of its terminals connected through solenoid coil 317 to thepositive terminal of voltage source 3%, the other terminal of the switchZ being connected directly to the negative terminal of source 3%,whereas the other terminals of switches X, C, V, B, N, M, comma andquestion mark are connected respectively to coils 392, 3%, 3M, 3%, 3%,CW7, 3th), Sal i. Whereas, as mentioned before, the coils $91-$16,inclusive, may be assembled as shown in Figure 4, with their actuatingmechanisms interlocked, the solenoid coils 315, 316, 317 may likewise beinterlocked and correspond with the other set of coils illustrated inFigure 2. In other words, the solenoid actuated mechanism which includethe coils Soliii inclusive, move the tens wheel 19 (Figure 2) todifferent adjusted positions depending upon which one of such coils isenergized, whereas the coils Said, 315, 317 effect movement of the unitswheel 11 to corres ondingly different adjusted positions. By this means,the forty characters illustrated in Figure 14 correspond to one of fortydifferent number which is indicated by the cooperating tens and unitswheels 19 and 11.

While the particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled the art thatchanges and modifications may be made without departing from thisinvention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fallWithin the true spirit and scope of this invention.

1 claim:

1. A control device of the character described having a rotor and astator; said stator comprising a -rrst series of circumferentiallyarranged contacts, a. sec -d series of circumferentially arrangedcontacts and a third series of circumferentially arranged contacts; saidrotor having a first series of circumferentially arranged contacts, asecond series of circumferentially arranged contacts and a third seriesof circumferentially arranged contacts, said second and third series ofcontacts on said rotor overlying and being disposed on opposite sides ofsaid first series of contacts, corresponding angularly positioned onesof said second and third series of contacts on said rotor beinginterconnected, an auxiliary contact mounted on said rotor; said first,second and third series of contacts on said rotor lying intermediate thecircumferential spacing of adjacent contacts of both said first andsecond series of contacts on said stator, said auxiliary contact on saidrotor being disposed laterally of said first series of contacts on saidrotor and leading, in a circumferential direction, the foremost one ofsaid first series of contacts on said rotor, and said auxiliary contacton said rotor engaging with contact, in succession, individual contactsin said third series of contacts on said stator upon rotation of saidrotor.

2. A control device of the character described comprising a stator and arotor; said rotor having a first series of contacts, a second and athird series of contacts on said rotor disposed laterally on oppositesides of said first series of contacts with corresponding angu larlypositioned ones of said second and third series of contacts overlyingtwo adjacent contacts in said first series, correspondingly angularlypositioned contacts of said second and third series of contacts on saidrotor being interconnected; said stator having a first and a secondseries of circumferentially arranged contacts thereon, each contact ofsaid first series of contacts on said stator bridging the lateraldistance between adjacent contacts of said first and second series ofcontacts on said rotor, each contact of said second series of contactson said stator bridging corresponding anguiarly positioned ones oflaterally disposed contacts of said first and third series of contactson said rotor, and all of the mentioned contacts on said rotor extendingcircumferentially a distance substantially equal to the circumferentialspacing of contacts in said first or second series of contacts on saidstator.

3. The arrangement set forth in claim 2 in which said stator includes athird series of contacts and said rotor has an auxiliary contact whichleads in a circumferential direction the foremost one of the contacts ofs id first series of contacts on said rotor, with said auxiliary contacton said rotor bridging, in succession, individual contacts of said thirdseries of contacts on said stator upon rotation of said rotor withrespect to said stator.

4. A control device of the character described comprising a stator and arotor; said rotor having a first series of circumferentially arrangedcontacts, a second and a third series of contacts on said rotor withcorresponding contacts of said second and third series lying on oppositesides of a pair of contacts of said first series and overlapping thesame, said stator having a first and a second series ofcircumferentially arranged contacts, all of said contacts on said rotorlying substantially between adjacent contacts of both said first andsecond series of contacts on said stator, with a corresponding angularlypositioned contact of said first series of contacts on said rotorinterconnecting contacts of said first and second series on said rotorand contacting only a particular contact in said first series ofcontacts on said rotor, and a contact in said second series of contactson said stator bridging contacts in said first and third series ofcontacts on said rotor and contacting only one contact in said firstseries of contacts on said rotor.

5. The arrangement set forth in claim 4 in which said rotor includes anauxiliary contact, said stator includes a third series of contacts, saidauxiliary contact leading in a circumferential direction the foremostone of the contacts of said first series on said rotor and contacting insuccession the individual contacts of said third series on said statorupon rotation of said rotor with respect to said stator.

6. A control device of the character described comprising a rotor and astator, said rotor having a first series of circumferentially arrangedcontacts, a second and a third series of circumferentially arrangedcontacts with corresponding angularly positioned contacts of said secondand third series mounted n opposite sides of said contacts of said firstseries of contacts and bridging the circumferential distance betweenadjacent contacts of said first series of contacts, the foremost contactof said first series of contacts leading in a circumferential directionthe first ones of said contacts of said second and third series ofcontacts, said stator having a first and a second series ofcircumferentially arranged contacts, with all of 1 the above-mentionedcontacts on said rotor being disposed between adjacent contacts of bothsaid first and second series of stator contacts.

7. The arrangement set forth in claim 6 in Which said rotor includes anauxiliary contact disposed laterally of 1 the contacts of said first,second and third series of contacts on said rotor with said auxiliarycontact leading in a circumferential direction said foremost contact ofsaid first series of contacts, and said stator having a third series ofcircumferentially arranged contacts contacting in succession saidauxiliary contact on said rotor upon rotation of said rotor with respectto said stator.

References Cited in the file of this patent UNITED STATES PATENTS1,306,410 Dawson et al. June 10, 1919 2,620,981 Benson et a1. Dec. 9,1952 FOREIGN PATENTS 207,973 Germany Mar. 12, 1909 76,633 Austria May15, 1918 394,789 Great Britain July 6, 1933

